diff options
| author | Kan Liang <kan.liang@linux.intel.com> | 2018-03-26 09:42:09 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 08:17:27 +0200 |
| commit | e8532355b2cf5e545afb43d6d5a77fb7ba191819 (patch) | |
| tree | b6a7e174fa38d31a9d7efdaa5622fc4a693db459 /tools | |
| parent | 9d434e579b3c5402cbc0f80c3f669f1d002a0722 (diff) | |
perf mmap: Fix accessing unmapped mmap in perf_mmap__read_done()
[ Upstream commit f58385f629c87a9e210108b39c1f4950d0363ad2 ]
There is a segmentation fault when running 'perf trace'. For example:
[root@jouet e]# perf trace -e *chdir -o /tmp/bla perf report --ignore-vmlinux -i ../perf.data
The perf_mmap__consume() could unmap the mmap. It needs to check the
refcnt in perf_mmap__read_done().
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: ee023de05f35 ("perf mmap: Introduce perf_mmap__read_done()")
Link: http://lkml.kernel.org/r/1522071729-16776-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/mmap.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index 91531a7c8fbf..0bda6dfd5b96 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -344,5 +344,11 @@ out: */ void perf_mmap__read_done(struct perf_mmap *map) { + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return; + map->prev = perf_mmap__read_head(map); } |